This invention relates to certain urea derivatives containing isocyanate groups and to a method for their production.
The reaction of 3-isocyanatomethyl-3,5,5-trimethyl-cyclohexylisocyanate (also known as isophorone diisocyanate or IPDI) with diamine in the molar ratio of 2:1 forms a compound which is insoluble in the usual solvents. The compound that forms is probably a urea adduct built of at least 3 molecule units. The question of solubility, however, is of great importance for the use of this reaction product as a cross-linking agent for polyesters and polyethers containing hydroxyl groups. A strong viscosity increase of the cross-linking system results from the insolubility of the adduct and the inhomogeneity conditioned thereby complicates processing considerably.